Ip Telephony With H.323: Architectures for Unified Networks and Integrated Services

by V. Kumar; Markku Korpi; Senthil Sengodan

• ISBN13: 9780471393436
• ISBN10: 0471393436
• Format: Hardcover
• Copyright: 2001-01-01
• Publisher: Wiley

Summary

This book presents end-to-end system basics for IP telephony-the technology that enables private data networks to provide extended communication services and multimedia transmission over standard phone lines. Written by the chief architects of H.323, the governing protocol for IP telephony, this book delivers the most authoritative coverage of what is considered the hottest topic in networking today. Network and telecommunications professionals will find clear discussions of the principles and implementations of next generation architectures and services, as well as comprehensive coverage of the related protocols, addressing and routing issues, interworking IP with legacy systems, deploying gateways, and more. Mobility, security, and QoS aspects of H.323 systems are also explained in detail.

Author Biography

VINEET KUMAR is a chief architect responsible for IP telephony and mobile Internet at Intel. He has been Principal Architect of H.323 at the ITU-T from its onset in 1995. <p> MARKKU KORPI is President, CTO, and founder of Cosini Technologies. He was previously Chief Systems Architect at Siemens where he designed multimedia networks. He served as editor of H.450. <p> L SENGODAN is the Manager of the Internet Multimedia Security Group at Nokia Research Center, Boston. He leads IP telephony and IP security-related projects at Nokia Research Center, and has made IP telephonyùrelated contributions to ITU-T, ETSI, IETF, and other bodies.

Table of Contents

Preface	xv
Acknowledgments	xvii
Introduction	1	(18)
Functional Entities	3	(2)
H.323 Protocols	5	(2)
H.323 System Model	7	(4)
Administrative Domain X	7	(2)
Administrative Domain Y	9	(1)
Administrative Domain Z	9	(1)
Call Scenarios	9	(2)
Book Outline	11	(6)
Multimedia Transport on IP Networks	11	(1)
Point-to-Point Call: Signaling	12	(1)
Multi-Point Conference	12	(1)
Inter-Domain Communication	13	(1)
Supplementary Services: Overview and Approach	14	(1)
Third-Party Supplementary Services in H.450	14	(1)
Call Diversion Services in H.450	15	(1)
Call Completion Services for Unsuccessful Calls in H.450	15	(1)
Stimulus Signaling	15	(1)
Service-Independent Transport by Using HTTP	15	(1)
Principles of Interworking	16	(1)
H.323 Security	16	(1)
H.323, Generic Security Protocols, and Firewalls	16	(1)
H.323 Mobility	16	(1)
QoS Principles and Application Level QoS	17	(1)
Network-Provided QoS for H.323	17	(1)
Recommended Reading	17	(1)
References	17	(2)
Multimedia Transport on IP Networks	19	(40)
Voice	19	(7)
Transmission of Digitized Voice	20	(1)
Voice Coders	20	(2)
Basic Attributes of Voice Coders	22	(2)
End-to-End Delay	24	(2)
Conversational Text	26	(1)
Text Transmission Using T.140 as a Coder	26	(1)
End-to-End Delay	27	(1)
Facsimile	27	(3)
G3 Facsimile Architecture	27	(1)
G3 Facsimile Communications Protocol	28	(2)
Video	30	(6)
Transmission of Digitized Video	30	(3)
Bit-Stream Syntax Overview	33	(1)
Video Coder Summary	34	(2)
Transport of Conversational Media on the Internet by Using RTP	36	(18)
RTP Header	39	(2)
RTP Payload	41	(10)
End-to-End Delay and Header Compression on the IP Network	51	(2)
Synchronization of Streams	53	(1)
Real-time Transport Control Protocol	53	(1)
Transport of Facsimile over the Internet	54	(2)
References	56	(1)
Problems	57	(2)
Point-to-Point Call: Signaling	59	(86)
Call-Signaling Protocol: H.225.0-Q.931	62	(7)
H.225.0-Q.931 Signaling	64	(2)
H.225.0-Q.931 Messages	66	(3)
Call-Control Protocol: H.245	69	(41)
Description of Some H.245 Messages	70	(29)
Scenarios	99	(11)
Call Control Embedded in Call Signaling	110	(5)
H.245 Tunneling	110	(1)
Fast Connect	111	(4)
The Registration, Admission, and Status Protocol: H.225.0-RAS	115	(19)
H.225.0-RAS Message Flows	117	(16)
H.225.0-RAS Transport Protocol	133	(1)
Call Models	134	(9)
Gatekeeper-Routed Call Signaling	135	(8)
References	143	(1)
Problems	143	(2)
Multi-Point Conference	145	(70)
Conference Basics	145	(8)
Conference Types	146	(2)
Network Configurations	148	(3)
Network Configurations Used in H.323	151	(2)
Conference Types Used in H.323	153	(1)
Small- and Medium-Scale Conferences Using H.323	153	(28)
Additions to Call Control Protocol-H.245	155	(11)
Additions to RTP	166	(4)
Additions to Call Signaling Protocol	170	(1)
Scenarios	171	(9)
Scalability of Voice and Video on the Access Link	180	(1)
Large-Scale Conferences Using RTP/RTCP and SDP	181	(29)
Session Description Protocol (SDP)	182	(5)
RTP Control Protocol (RTCP)	187	(23)
Large-Scale Conference Using H.332	210	(2)
Conference Configuration	210	(1)
Extensions to SDP	211	(1)
Invitation from the Panel	211	(1)
Generation of SSRC Identifiers in H.323 and RTP	212	(1)
Recommended Reading	212	(1)
References	212	(1)
Problems	213	(2)
Inter-Domain Communication	215	(30)
Organization of Administrative Domains	217	(3)
H.225.0 Annex G Messages and Message-Flows	220	(5)
Address Templates for Routing Calls	225	(10)
Pre-Call Population of Address Resolution Table	235	(3)
Border Element Discovery	235	(1)
Service Relationship Establishment	235	(2)
Populating the Address Resolution Table	237	(1)
Address Resolution, Authorization, and Usage Reporting during the Call	238	(4)
Address Resolution and Authorization	239	(1)
Resource Usage Reporting	240	(2)
Recommended Reading	242	(1)
Reference	242	(1)
Problems	242	(3)
Supplementary Services: Overview and Approach	245	(30)
Purpose of Supplementary Services	246	(1)
Categories of Call Control Applications	247	(4)
First-Party Call Control Applications	248	(1)
Third-Party Call Control Applications	249	(1)
Call Management Applications	250	(1)
Signaling Architecture for Services in H.323	251	(7)
A Centralized Approach Using Stimulus Signaling	252	(2)
A Web-Based Approach Using HTTP	254	(2)
Distributed Peer-to-Peer Approach Using H.450	256	(2)
Introduction to H.450 Supplementary Services	258	(14)
Requirements for H.450	258	(2)
The Embedding of H.450 in H.323 System Architecture	260	(1)
The Status of H.450 Recommendations	261	(1)
H.450.1-Generic Functional Protocol	261	(6)
H.450.12-Common Information	267	(1)
H.450.8-Name Information	268	(4)
Recommended Reading	272	(1)
References	272	(1)
Problems	273	(2)
Three-Party Supplementary Services in H.450	275	(26)
General	275	(1)
Call Hold	276	(7)
Near-End Hold Invocation and Operation	277	(2)
Remote-End Hold Invocation and Operation	279	(2)
Near-End Hold/Retrieve Performed by Gatekeeper	281	(1)
Remote-End Hold/Retrieve Performed by Gatekeeper	281	(2)
Consultation	283	(1)
Alternating	284	(1)
Call Transfer	285	(5)
Invocation and Operation	285	(1)
Signaling Protocol	286	(1)
Unsuccessful Transfers	287	(1)
Call Transfer Performed by Gatekeeper	288	(2)
Consultation Transfer	290	(5)
Invocation and Operation	290	(1)
Signaling Protocol	291	(1)
Consultation Transfer Performed by Gatekeeper	292	(3)
Conference Out of Consultation	295	(3)
Invocation and Operation	296	(1)
Signaling Protocol	297	(1)
Recommended Reading	298	(1)
References	299	(1)
Problems	299	(2)
Call Diversion Services in H.450	301	(16)
General	301	(3)
Common Characteristics of Call Diversion Services	302	(1)
Remote Registration of Call Forwarding	303	(1)
Call Forwarding on All Calls and on Busy	304	(3)
Invocation and Operation	305	(1)
Signaling Protocol	306	(1)
Call Forwarding on No Reply and Call Deflection	307	(5)
Invocation and Operation	307	(1)
Signaling Protocol	308	(1)
Call Forwarding Performed in the Gatekeeper	309	(3)
Call Diversion when Terminal Is Out of Service	312	(1)
Interaction with Other Supplementary Services	313	(1)
References	314	(1)
Problems	315	(2)
Call Completion Services for Unsuccessful Calls in H.450	317	(30)
General Information	317	(6)
The Treatment of Unsuccessful Calls	319	(2)
The Definition of Busy and the Handling of Multiple Calls	321	(2)
Call Waiting-H.450.6	323	(3)
Invocation and Operation	324	(1)
Signaling Protocol	324	(1)
Conclusion of the H.450.6 Call Waiting Services	325	(1)
Message Waiting Indication-H.450.7	326	(3)
Invocation and Operation	326	(1)
Signaling Protocol	327	(1)
Conclusion of the H.450.7 Message Waiting Indication Services	328	(1)
Message Waiting Callback-H.450.7	329	(2)
Invocation and Operation	329	(1)
Signaling Protocol	329	(2)
Conclusion of the H.450.7 Message Waiting Callback Services	331	(1)
Call Completion Services-H.450.9	331	(5)
Invocation and Operation	331	(2)
Signaling Protocol	333	(2)
Additional Implementation Aspects	335	(1)
Conclusion of the H.450.9 Call Completion Services	335	(1)
Call Offering-H.450.10	336	(4)
Invocation and Operation	336	(1)
Signaling Protocol	337	(3)
Conclusion of the H.450.10 Call Offering Services	340	(1)
Call Intrusion-H.450.11	340	(4)
Invocation and Operation	341	(1)
Signaling Protocol	342	(2)
Conclusion of the H.450.11 Call Intrusion Service	344	(1)
References	344	(2)
Problems	346	(1)
Stimulus Signaling	347	(24)
General Information	347	(3)
Variants of Stimulus Signaling	348	(1)
Centralized versus Distributed Stimulus Call Control	349	(1)
H.323 Stimulus Signaling	350	(13)
The Goals	350	(1)
Programming Model	351	(3)
Functional Units	354	(1)
Protocol Framework	355	(8)
Stimulus Signaling Protocol in H.248	363	(5)
The H.248 Connection Model	363	(5)
Recommended Reading	368	(1)
References	369	(1)
Problems	369	(2)
Service-Independent Transport by Using HTTP	371	(14)
Characteristics and Purpose	371	(2)
Comparison to Stimulus Signaling	372	(1)
Supported Features	373	(1)
Application Scenarious	373	(2)
Protocol Mechanisms	375	(7)
Non-Call-Related Services Control	376	(2)
Call-Related Service Control	378	(4)
Recommended Reading	382	(1)
References	382	(1)
Problems	383	(2)
Principles of Interworking	385	(20)
QSIG Interworking with H.323	387	(11)
QSIG Gateway-Layer Architecture	388	(1)
Gateway Signaling	389	(1)
Interworking of Consultation Transfer	390	(6)
The Interworking of Single-Step Call Transfer	396	(2)
ISUP Interworking with H.323	398	(3)
ISUP Gateway-Layer Architecture	399	(1)
Gateway Signaling	399	(2)
Trunking Gateways	401	(1)
QSIG Trunking	401	(1)
ISUP Trunking	401	(1)
BICC Interworking	402	(1)
Residential H.323 Gateways	402	(2)
References	404	(1)
Problems	404	(1)
H.323 Security	405	(38)
Security Services for H.323 Systems	405	(1)
Generation of a Secret Key	406	(4)
Key Generation from a Password	407	(1)
Key Generation by Using Diffie-Hellman	408	(2)
User Authentication	410	(5)
Authentication by Shared Secret-Based Encryption	411	(2)
Authentication by Shared Secret-Based Hash	413	(1)
Authentication by Using a Digital Signature	414	(1)
Message Authentication/Integrity	415	(2)
Mechanisms to Achieve Message Integrity	416	(1)
Securing H.225.0 and H.245 Channels	417	(2)
Securing the H.225.0 Channel	417	(1)
Securing the H.245 Channel	417	(2)
Secure H.235 Control Channel	419	(1)
Security Capability Exchange	419	(2)
Receiver Requesting a Security Mode	421	(1)
Media-Stream Encryption	421	(11)
Opening a Logical Channel for the Encrypted Media Stream	423	(1)
Encryption Key Generation, Distribution, and Refresh	424	(4)
Use of RTP-Based Techniques for Media-Stream Encryption	428	(4)
Use of IPSec for Media-Stream Encryption	432	(1)
Anonymity	432	(3)
Security Profiles	435	(4)
Baseline Security Profile	436	(1)
Signature Security Profile	437	(2)
Recommended Reading	439	(1)
References	439	(1)
Problems	440	(3)
H.323, Generic Security Protocols, and Firewalls	443	(40)
Generic IP Security Protocols and Algorithms	443	(15)
Security Protocols	444	(10)
Security Algorithms	454	(4)
Firewall Traversal	458	(13)
Issues Surrounding Firewall Traversal of H.323 Streams	459	(2)
Types of Firewalls	461	(8)
Network Topology and Firewall Placement	469	(2)
Private Addressing	471	(4)
Network Address Translation	471	(2)
Realm Specific IP	473	(2)
Using RADIUS within H.323 Systems	475	(4)
RADIUS Overview	475	(1)
H.323 and RADIUS	476	(3)
Recommended Reading	479	(1)
References	480	(1)
Problems	481	(2)
H.323 Mobility	483	(20)
Types of Mobility	483	(4)
User Mobility	484	(1)
Terminal Mobility	485	(1)
Service Mobility	485	(2)
H.323 Mobility Architecture	487	(5)
Initial Gatekeeper Discovery and Registration	487	(2)
Location Update	489	(1)
Call Signaling to an Endpoint	490	(1)
Authenticating Function (AuF)	491	(1)
Interworking Function (IWF)	491	(1)
User Mobility between PLMN and H.323 Systems	492	(7)
Subscriber Identifiers	492	(1)
Achieving User Mobility with IWF	493	(6)
Non-Application Layer Wireless Issues	499	(2)
Error Correction	499	(1)
Link and Network Layer Handoff	500	(1)
Recommended Reading	501	(1)
References	501	(1)
Problems	502	(1)
QoS Principles and Application Level QoS	503	(20)
Motivation and Drivers	503	(3)
Factors Affecting H.323 System Quality	506	(7)
Quality in the RAS, H.225.0, and H.245 Channels	508	(1)
Quality in the Media Stream	509	(4)
Application Level QoS	513	(6)
Feedback Mechanisms	513	(2)
Source Acting on the Feedback	515	(4)
Overhead Reduction Techniques	519	(1)
IP/UDP/RTP Header Compression	519	(1)
Multi-frame packets	519	(1)
Recommended Reading	520	(1)
References	520	(1)
Problems	521	(2)
Network Provided QoS for H.323	523	(52)
Motivation	523	(4)
Basic Network QoS Building Blocks	527	(14)
Traffic Characterization Using Token Bucket	527	(6)
Packet Classifiers	533	(1)
Rate Controllers	534	(2)
Packet Schedulers and Queue Management	536	(5)
RAS Operations for H.323 QoS	541	(3)
H.323 Entity Controlling QoS	541	(3)
Call Bandwidth	544	(1)
RSVP/Intserv Based QoS for H.323 Systems	544	(12)
Integrated Services (Intserv)	545	(4)
RSVP	549	(3)
H.323 and RSVP/Intserv	552	(3)
H.323 with RSVP/Intserv over 802 LANs	555	(1)
Diffserv-based QoS for H.323 systems	556	(9)
Default PHB	559	(1)
Class Selector PHB	559	(1)
Assured Forwarding (AF) PHB	559	(3)
Expedited Forwarding (EF) PHB	562	(3)
Policy, Resource Management, and Multi-Domain Issues	565	(5)
QoS Functional Entities and Reference Points	565	(1)
Role of Policy in H.323 QoS	566	(1)
Scenario 1	567	(1)
Scenario 2	568	(1)
Scenario 3	569	(1)
EP/GK Controlled QoS	569	(1)
Recommended Reading	570	(1)
References	571	(1)
Problems	572	(3)
Glossary	575	(8)
Acronym List	583	(8)
Index	591